How can I scale a UV Island within a precise border in my low-res texture?
here is an idea, but just to warn you, I am taking advantage of the &quot;ANY help would be highly appreciated.&quot;  Hope it is worth it :)
I have a simple repeating texture:

Now I have created an example mesh like your arm:

What I have done to the corner edges is I have selected them, hit ctrl-E, and select &quot;Mark Seam.&quot;  Then I selected the entire mesh and hit &quot;u&quot;, and then I selected from the drop-down, &quot;unwrap.&quot;
I then applied the texture to the arm.  Now select the entire mesh, go to the UV image editor, select all of the mesh in the UV editor window, and scale it to the appropriate size.
The texture will not be aligned on each side, however.  I fixed this by aligning it manually.  This is how: you select one whole side at a time, move over to the UV image editor, select the mesh, and move it on the x and y axis.  This will change the position that the texture is on the mesh, as shown below.  Make sure, when moving the texture, that you are moving the mesh on the UV image editor window, and NOT on the 3D view window.

This is a lot more manual work, and I hope that I did not lose you.  If I did, please say so, and I will edit this post.  Here is the result you will get:

If this doesn't exactly apply to your problem, then don't feel bad to clue me in, and I will try to help.